John and Carole Costello established Costello Aluminium in October 1979. The company went from strength to strength and grew rapidly. Sons Oakley and Barclay Costello now run Costello Windows. Costello Windows manufactures every facet of the final product in-house from a 13 acre factory located on a beautiful site along the Glin Corbery river valley one mile from the picturesque village of Glin in County Limerick. Costello Windows Limited originally known as Costello Aluminium and UPVC started out with 4 employees, mainly family members. 30 years later the workforce had grown to 230. The recession hit the construction industry, including the window and door business resulting in the reduction of the workforce. Now Costello Windows employ a set of 50 skilled employees each member has vast experience and are exceptionally talented people, i.e. the best of the best. We have a specific belief at Costello Windows that quality, innovation and service are vital to success, every day we look to improve, innovate and produce standards of excellence. Our strategy at Costello Windows is as follows, the customer is king.